Intravascular ultrasound imaging systems (IVUS) are used to obtain ultrasound images inside a patient's body. An IVUS system typically includes an ultrasound catheter having a flexible catheter sheath adapted for insertion into the vascular system of the patient. To obtain ultrasound images, the catheter comprises an imaging core received within a lumen of the catheter sheath. The imaging core comprises an ultrasound transducer connected to the distal end of a flexible drive cable that extends to the proximal end of the catheter through the catheter lumen. The drive cable is used to rotate and longitudinally translate the transducer within the catheter lumen to obtain images at different positions within the patient's body.
An IVUS catheter is commonly advanced through a guide catheter to a desired site within the patient's body. A problem with existing catheters is that they are adapted for use with guide catheters that are 6 French or greater in diameter. As a result, these catheters can not be used to access desired sites within the patient's body through narrower blood vessels, e.g., the radial artery, without risk of vessel spasm.
Therefore, there is a need for a low profile intravascular catheter that can be used with guide catheters that are 5 French or smaller in diameter. Such a catheter would allow easier access to sites within the patient's body through the radial artery.